Achieving least cost GHG abatement opportunities in Australian grains farms

The Australian ‘Carbon Farming Initiative’ (CFI) aims to encourage new farming practices that can store carbon, or reduce greenhouse gas emissions. Practices that mitigate greenhouse gas emissions include storing carbon in vegetation by planting trees or perennial shrubs, and storing carbon in soils through (for example) use of perennial crops and pastures, no-till systems, rotational grazing and pasture cropping. It is unclear how changing agricultural practices will affect farm businesses. This research aims to estimate what levels of abatement and carbon sequestration are economically feasible for Australian grains farms.

This project will estimate the net, whole-farm greenhouse gas (GHG) mitigation balance, including soil carbon sequestration, of different management activities applicable to Australian grains farms, taking into account the trade-offs and/or interactions associated with farming practicalities and economics.

The project will estimate how much on-farm GHG mitigation could be achieved through comprehensive modelling of mitigation and profitability of different farming systems management scenarios (e.g. no till, grain and graze systems, fertiliser management). The modelling will be undertaken for case study farms, established with Farmer Groups in Australia’s major grain growing regions. Initially, the biophysical and economic characteristics of representative case study farms will be determined. The datasets developed from this activity will underpin subsequent farming systems modelling in the Agricultural Production Systems Simulator (APSIM) farming systems model.

Information from APSIM will subsequently be integrated into a whole-farm economic model developed in this project. The model will be used to simulate the whole-farm financial effects of practices to mitigate GHG emissions, and to identify the most profitable and productive farm management systems applicable to Australian grains farms that maximise greenhouse gas abatement.

An additional objective of this project is to improve the capability to predict the effects of soil organic matter on crop growth and hence farm profitability, by incorporating expressions relating organic matter to soil function in the APSIM model. This objective is pursued in collaboration with scientists from the Global Research Alliance on Agricultural Greenhouse Gases.

The project will further consider how different future climates may influence the amount of carbon sequestration and farm profitability. Analyses of net GHG mitigation under different climate scenarios can identify whether the amount of carbon sequestered in soils might change in response to future climates, and whether higher carbon and improved soil function may help farmers adapt to future climates.

This project will provide policy makers and farmers with a comprehensive understanding of how soil carbon sequestration, GHG abatement and farm profitability in grains farms could be affected by a range of farm management systems.  It will thus allow these stakeholders to maximise the impact of potential GHG abatement and farm profitability in grains production.

Collaborator/s

  • Dr. Peter Thorburn, Commonwealth Scientific and Industrial Research Organisation; CSIRO
  • Grains Research and Development Organisation (GRDC)
  • AgResearch Limited